Hermann Cornelia A, Mayer Michael, Griesche Christian, Beck Franziska, Baeumner Antje J
Institute for Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.
Analyst. 2021 Feb 7;146(3):997-1003. doi: 10.1039/d0an02027c. Epub 2020 Dec 9.
Bearing multiple functionalities dramatically increases nanomaterial capabilities to enhance analytical assays by improving sensitivity, selectivity, sample preparation, or signal read-out strategies. Magnetic properties are especially desirable for nanoparticles and nanovesicles as they assist in negating diffusion limitations and improving separation capabilities. Here, we propose a microfluidic method that reliably labels functional nanovesicles while avoiding the risk of crosslinking that would lead to large conglomerates as typically observed in bulk reactions. Thus, the carboxy groups of bi-functional biotinylated fluorescent liposomes were activated in bulk. They were then covalently bound to amino group presenting magnetic beads immobilized through a magnetic field within microfluidic channels. Microfluidic design and coupling strategy optimization led to a 62% coupling efficiency when using 1 μm magnetic beads. The yield dropped to 13% with 30 nm magnetic nanoparticles (MNPs) likely due to crowding of the MNPs on the magnet. Finally, both populations of these tri-functional liposomes were applied to a biological binding assay demonstrating their superior performance under the influence of a magnetic field. The microfluidic functionalization strategy lends itself well for massively parallelized production of larger volumes and can be applied to micro- and nanosized vesicles and particles.
具备多种功能可显著提高纳米材料的能力，通过改善灵敏度、选择性、样品制备或信号读出策略来增强分析检测。磁性对于纳米颗粒和纳米囊泡尤为重要，因为它们有助于消除扩散限制并提高分离能力。在此，我们提出一种微流控方法，该方法能可靠地标记功能性纳米囊泡，同时避免交联风险，而交联会导致形成通常在批量反应中观察到的大聚集体。因此，双功能生物素化荧光脂质体的羧基在批量反应中被激活。然后，它们与通过微流控通道内的磁场固定的带有氨基的磁珠共价结合。微流控设计和偶联策略优化使得使用1μm磁珠时偶联效率达到62%。使用30nm磁性纳米颗粒（MNPs）时产率降至13%，这可能是由于MNPs在磁体上拥挤所致。最后，将这两种三功能脂质体群体应用于生物结合检测，证明了它们在磁场影响下的优越性能。微流控功能化策略非常适合大规模并行生产更大体积的产品，并且可应用于微米和纳米尺寸的囊泡及颗粒。
